Elevator-door lock



F. A, BOEDTCHER.

ELEVATOR DOOR LGCK..

APPLICATION FILED IAN. I7x 1919.

UNITED -STATES PATENT OFFICE.

FRANZ A. BOEDTCHER, OF BERGENFIELD, NEW JERSEY.

To all fui/1,0m t may concern.'

Be it known that l, FRANZ A. BonDrcI-IER, a citizen of the United States, residing in Bergeniield, county of Bergen, and State of New Jersey, have invented a certain new and useful Elevator-Door Lock, of which Vthe following 1s a specification.

This invention is an elevator door lock and is intended, more particularly, for use On shaft doors Yor gates of elevators. In a normal operation o`f shaft doors the elevator operator is apt to become rather careless inthe closing of theV doors at the various floors, and it is not infrequent that these doors are slammed shut so violently that they rebound into partially open position before latches, normally employed to lock them shut, can come into effective operation. As a result the car, as it proceeds upon its way, leaves the door slightly open, with the result that a dangerous condition exists. Children are apt to stray through the opening and fall through the shaft, or curious persons waiting at that particular floor for the next passage of the car not infrequently stick their heads through the opening just in time to be struck by the passing car. Accordingly, in many cities, the laws provide for certain safety appliances intended to obviate the occurrence of accidents of the character specified.

In view of the foregoing, means, generally electric, are usually provided for precluding the movement of the elevator car away from a floor, unless the shaft door at said iioor is previously closed and locked.

he present invention, however, overcomes the lforegoing disadvantages by purely mechanical means adapted to insure `the locking of the door in a fully closed position, or, if the door should slightly open due to a sharp rebound, it will be locked in `such partially open condition so that further opening of the door is impossible.

The object of the present invention, is, therefore, to provide a simple mechanical expedient for locking a door in fully closed position, as well as in any intermediate position between those of fully opened and fully closed. Y

Features of the invention other than those specified, will be apparent from the hereinafter detailed description taken. in conjunction with the accompanying drawm s.

11th@ accompanying drawings, have Specification of Letters Patent.

ELEVATOR-DOOR LOCK.

Patented Aug. 24, 1920.

Application filed January 17, 1919. Serial No. 271,615.

to be understood as illustrative only, and

not as defining the limits of the invention.

Figure l is a view of the interior of an elevator shaft, showing just a sufficient fragment of the same to illustrate the application of the present invention thereto. In this figure the door casing of a floor Vdoor is shown; the door is shown in fully opened position;

Figs. 2, 3 and 4c are fragmental views, similar to that of Fig. l, but illustrating the mechanism of the present invention in different operative positions.

Referring to the drawings, A designates the casing of an elevator shaft door which is normally closed by means of a sliding door or gate B, mounted and actuated in any suitable manner. The door is here shown of sliding type. The means for operating the door are immaterial tothe present invention, and, accordingly, are omitted in the interest of clearness.

Mounted on the upper inner surface of the door, and preferably adjacent the forward edge thereof, is a gravity latch C, pivoted at c and weighted at c so that it will normally gravitate into the position shown in Fig. l, wherein the nose of the latch protrudes above the upper edge of the door. On the casing A is a locking plate D, here shown as embodying a metal plate bent at two right angles and secured to the casing by bolts or lag screws d. The plate D has a depending flange (Z2 in the lower edge of which is formed consecutive serrations d, so that said edge is of a saw-tooth configuration. The plate D is so proportioned that the saw-tooth edge of the flange d2 ywill lie in the path of the latch C, mounted on the door, and these parts are adapted to coperate with one another for the purpose of automatically locking the door against retrograde movement after the same has been closed. The flange Z2 may be of with one of the adjacent serrations d and rie lock the door against further opening. However, in practice, it is found that, since the latch during the closing operation of the door is in contact with the serrations and riding idly thereover, it will invariably engage the first serration and will lock the door in closed position. Moreover, if the operator gives the vdoor insuli'icient impetus to entirely close it, it will be locked in its foremost advanced ,position and cannot be opened from the corridor side of the shaft. In fact, it can only be released from the shaft side by the means next to be described. .Y The weighted portion c on the latch C is 'preferably in the form of a flange projecting below the body portion of the latch, 'and this flange is availed of a guide for the operations of the latch relative to a link ll by which it may be manually operated by the elevator attendant. The link E is pivoted at e at one of its ends and at its other end has pivoted connection with a push rod F, with the lower end of which is associated an operating handle G. v

In the normal operation of the device, the door, when in'open'position, to allow of the entrance or exit of passengers from the car, is as'shown in.. Fig. l, the latch C being removed frein locking plate D, and the weighted end of said latch is supported on the link E. When the door is movedl to vthe closed position, the latch will ride idly over the saw-tooth edge of the locking plate after the manner shown in Fig. 4, until the door comes to its closed, or partially closed positiomat which time the latch will engage with one ofthe serrations clshown in Fig. 2. The parts will remain in these relativev positions until the elevator operator desires to reopen the door through the manual forcing down of the handle Gr, at which time the link E will be tilted up for the purpose of rocking the `latch on its pivot c free from engagement with `the locking plate as shown in Fig. 3, at which time unobstructed -retrograde movement of the door may be had.

lVhilethe door locking means hereinbefore described has been referi'ed to as entirely independent of the door closing and opening' devices, said door may, nevertheless, be opened and closed through the grasping of the handle Gr by the operator and his bodily movement of the door through this medium. ln fact, the handle G may partake various forms, so long as it fulfils the4 function of operating the push'rod F. I

The use of a pawl and ratchet arrange- Vment on elevator doors is not broadly new,

but in all prior constructions7 these parts were so arranged that it was impossible to lock lthe door in a fully closed position lthrough the employment these elements,

and la separate and independent locking means had to kbe provided to lock the door fully closed." The' function of the pawl and ratchet devices heretofore employed have been merely to lock the door in a partially open position, in case the 'door had not been Y fully closed, the mere act of fully closing the door, automatically rendering the pawl and ratchet arrangements, inoperative as a locking medium. The present invention provides unitary means for locking the door in either closed or partially closed position and entirely obviates the necessity of separate and independent locking means, such as has heretofore universally been the'case.

What I claim as new and ,desireto secure by Letters Patent is: Y

l. An elevator door lock embodying a serrated member adapted to be secured to a door casing, a coperating gravity latch pivoted on the door associated with said casing, and adapted to normally gravitate into engagement with one of the serrations of said member,.when the door is in closed vor partially closed position, to lock the same against retrograde movement, a manually operable push rod, and a member for operatively associating the push rod with the latch, said member serving to normally maintain'the Vlatch in a position to engage with the serrated member to lock the door in Yclosed or partially closed position, and being tially closed position to lock the saine against retrograde movement, Y a pivoted member for limiting the vpivotal movement of the latch under the force of gravity, to

position wherein it will normally cooperate with the serrated member, and'manually operable means associated withv the pivoted limiting member for actuating the same to Aoscillate the latch against the force of gravity out of coperative relation with the serrated member. Y Y Y '3. An elevator doo-r lock embodying a serrated Imember adapted tobe secured to a door casing, a latch pivoted Von the door associated withfsaid cas'ing,a link for manually actuating said latch, said latch being provided with a flange serving to maintain the latch and link in cooperative relation and simultaneously normally causing the 'latch to gravitate'into cooperative relation with the serrated member when the door is 'in closed or partially closed position to lock the same and a manually operated push rod associated with the link for moving VVthe latch, against the force of gravity, into a position free from engagement with the serrated member to allow of free opening of the door.

4. An elevator door lock embodying a serrated member adapted to be secured to a door casing, a latch pivoted on the door associated with said casing, a link for manually actuating said latclnsaid latch being Aprovided with a flange serving to maintain the latch and link in coperative relation and simultaneously normally causing the latch to gravitate into coperative relation with the serrated member when the door is in closed or partially closed position to lock the same, a push rod for operating said link and a manually operated handle associated with the push rod, whereby the operations of the handle are transmitted through the push rod and link to oscillate the latch into a position wherein it is free from engagement with the serrated member `for the purpose of allowing free opening of the door.

In testimony whereof I have signed my name to this specilication.

FRANZ A. BOEDTCHER. 

